634666889 has 4 divisors (see below), whose sum is σ = 634731024. Its totient is φ = 634602756.

The previous prime is 634666867. The next prime is 634666927. The reversal of 634666889 is 988666436.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 634666889 - 2²⁸ = 366231433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (634666849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13727 + ... + 38180.

It is an arithmetic number, because the mean of its divisors is an integer number (158682756).

Almost surely, 2^634666889 is an apocalyptic number.

It is an amenable number.

634666889 is a deficient number, since it is larger than the sum of its proper divisors (64135).

634666889 is a wasteful number, since it uses less digits than its factorization.

634666889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64134.

The product of its digits is 8957952, while the sum is 56.

The square root of 634666889 is about 25192.5959162608. The cubic root of 634666889 is about 859.3734795944.

The spelling of 634666889 in words is "six hundred thirty-four million, six hundred sixty-six thousand, eight hundred eighty-nine".